California Code, Fish and Game Code - FGC § 5672

Upon the determination by the State Department of Public Health that the area is or may be subject to sewage contamination, and that the taking of shellfish from it does or may constitute a menace to the lives or health of human beings, it shall ascertain as accurately as it can the bounds of the contamination, and shall post notices on or in the area describing its bounds and prohibiting the taking of shellfish therefrom.

The taking of shellfish from the area is unlawful after the completion of the publication of the notices as prescribed in this article.